Capsule technology continues to be subject to development and improvements. In its basic form, standard containers for pharmaceuticals or other powdered, granular or liquid substances (generally referred to as telescope-type or two-piece capsules) include a tubular-shaped and/or cylindrically-shaped first part, namely a cap part, which is closed on one end and open on the other opposite end. A tightly fitting second part of similar shape, namely the body part, is of smaller diameter than the cap part and is typically telescopically engaged therein to form the overall dosage form or two-piece capsule. Similar capsule technology may be used to generate multi-compartment capsules.
Delayed release in capsule technology is highly desirable since it permits to store within the capsule active materials that are normally acid instable and/or cause unpleasant side effects when reacting at stomach pH.
A number of ways for improving acid resistance of capsules have been described in the literature.
For example, EP111738661, describes a coated hydroxypropyl methylcellulose (HPMC) comprising capsule with delayed release properties.
US2012/288562A1 as further example, describes an acid resistance capsule for delayed release by forming a capsule shell of an HPMC comprising material in combination with a gelling aid in order to provide such delayed release without additional coating of the capsule being necessary.
Aside from coating and capsule shell formulations, other methods of improving delayed release of capsules has been achieved by banding capsules on the juncture between capsule cap and capsule body, as exemplified in EP1942878A2.
Although, acid resistance and delayed release has been successfully improved over time via formulation specific developments, including by surface modification and/or by capsule shell composition, a need still remains to further develop a capsule design/shape that by nature of its design further aids delayed release.
In terms of capsule design, the known dosage forms may be classified in two distinct design types: the first comprise mono-compartment dosage forms, the second comprises multi-compartment dosage forms.
Known single (or mono) compartment dosage forms are typically in the form of classic two-piece capsules comprising a body and a cap, as described for example in EP086106161. In the context of delayed release, these designs however do not further improve delayed release since there is a single “wall”/shell that must be dissolved before the active stored therein is released.
Multi-compartment dosage forms are known and are generally used for storing one or more incompatible components therein.
Some multi-compartment dosage forms are in the form of multiple two-piece capsules stored within one another. Generally this involves a larger two-piece capsule forming the outer shell of the dosage form and one or more smaller two-piece capsules therein storing different mediums therein. An example of this arrangement is described in EP1301178B1. Disadvantages of this arrangement include dislocation of the inner capsules with respect to the outer capsule which may result in damage of the content and/or capsules themselves during handling, overall size limitations of the dosage form, and large spacing/compartment between the inner and outer capsules.
Other multi-compartment dosage forms, such as described in EP2211820B1, are in the form of two-piece capsules with a main cap and a main body being joined to form a first compartment and a further body joined to the outer surface of the aforementioned main body to form a second compartment. Disadvantages of this arrangement include increased overall volume size of the dosage form (particularly overall length of the same) which may be undesirable for swallowability, risk of premature disengagement of the further body from the main body with subsequent spill of the content during handling, as well as requiring complex filling processes in order to fill and assemble the final product. In the context of delayed release, also such arrangements fail to bring added benefits because only a single “wall”/shell must be dissolved before the active stored therein is released.
Therefore there still remains a need for a dosage form article that overcomes the problems of the prior art and in particular allows for effectively improving delayed release of its contents whilst minimizing overall size of the dosage form and maximizing the amount of useful actives that can be stored therein.